Ectopically expressed PIR-B on T cells constitutively binds to MHC class I and attenuates T helper type 1 responses -- Imada et al. 21 (10): 1151 -- International Immunology
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For permissions, please e-mail: journals.permissions oxfordjournals.org Ectopically expressed PIR-B on T cells constitutively binds to MHC aggregation I and attenuates T helper type 1 responses Michiyo Imada 1, Kyoko Masuda 2, Rumi Satoh 2, Yumi Ito 1, Yoshiyuki Goto 1, Takayuki Matsuoka 1, Shota Endo 1, Akira Nakamura 1, Hiroshi Kawamoto 2 and Toshiyuki Takai 1 1 Branch of Experimental Immunology, Faculty of Development, Aging and Cancer, Tohoku University, Seiryo 4-1, Sendai 980-8575, Japan 2 Laboratory for Lymphocyte Development, RIKEN Test Centre for Allergy and Immunology, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan Letter to: T.
Takai; E-mail: tostakai at idac.tohoku.ac.jp Activated mature T cells induce changeable inhibitory receptors implicated in maintaining peripheral tolerance in response to the trans -acting ligands.
Interestingly, paired Ig-like receptor (PIR)-B, an inhibitory MHC crowd I receptor on B cells and myeloid cells, could be involved in regulating early T cell boost thanks to epitope for PIR is detected on pre-thymic T NK progenitors nevertheless not on thymocytes or mature T cells.
We hypothesized that PIR-B is not single a regulator for T cell process on the other hand is further detrimental provided expressed on mature T cells. Here we demonstrated, using PIR-B-deficient fetuses, that PIR-B is actually expressed on the T cell progenitors on the contrary failed to make its distinctive roles in the development. Forced term of PIR-B in thymocytes and mature T cells very resulted in no abnormalities in development.
However, upon antigenic or allogeneic stimulation, peripheral T cells with the ectopic PIR-B showed reduced T h type 1 responses due to the suppression of proximal TCR signaling by constitutive binding of PIR-B to MHC party I on the corresponding cell surface. Our findings propose that T cell signal of PIR-B with the cis -interacting MHC troop I is strictly prohibited in periphery so as to secure immediate proof responses.
Keywords: immunoregulatory receptor, T cell differentiation, T cell suppression, tolerance Transmitting editor : T. Kurosaki Received 2 Hike 2009, universal 24 The middle of summer 2009.
